Absorbent material for explosives and resulting explosives



Patented Oct. 28, 1930 HERBERT C. BUGBIRD, OF RICHMOND, 'NEW YORK ABSORBENT MATERIAL FOR EXPLOSIVES AND RESULTING EXPLOSIVES No Drawing. Application filed November 1, 1924, Serial No. 747,365. Renewed March 17, 1927.

My present invention relates to absorbent material for explosives, especially explosives embodying liquid oxygen, and to the resulting explosive or explosive cartridge utiliz- 5 ing such absorbent material, and aims to devise a material for the purpose specified above which is easy and convenient to pre pare, which possesses the necessary absorptive properties to a very high degree, which 0 is economical and readily available in large quantities at market prices sufficiently low to permit its economical use for the desired purpose, which yields an explosive or explosive cartridge of high power and efli- 5 ciency, and which possesses other desirable properties subsequently pointed out in detail hereinafter.

In the accompanying specification I shall describe an illustrative embodiment of the 0 method of the present invention as used for the purpose of preparing the explosive material of the present invention. In the ac companying specification I shall also describe an illustrative embodiment of the absorbent material and of the resulting explosive or explosive cartridge. It is, however, to be clearly understood that my invention is not'limited to the specific embodiments thereof herein described for the purpose of illustration only.

Before describing the aforesaid illustrative embodiments of the present invention in detail, it may be desirable briefly to point out certain shortcomings of the prior art so far as they relate to the subject matter of the present invention. Hitherto it has been proposed to utilize for explosives and explosive cartridge-s incorporating liquid oxygen, absorbent materials which have either been 9 expensive, or which have been unsatisfactory for other reasons, particularly due to the fact that slight variations inthe method of producing such absorbent materials often yielded absorbent materials differing widely 5 in their properties, such as their specific gravities and degrees of absorptiveness, with equivalent variations in the properties of the final explosives or explosive cartridges utilizing such absorbent materials. The re- 0 sultin'g products were accordingly lacking in uniformity, and often unreliable and sometimes altogether unsuitable in use for the purpose for which they were intended.

I have discovered, and proven by a series of tests, that the residues obtained by leachmg to substantial freedom from water-soluble substances (principally alkali carbonate) the carbonized granular mass obtained by carbonizing the liquor derived from the treatment of wood chips or other ligneous material with heated caustic alkalies (as in the manufacture of wood pulp by the soda or alkaline process, after the resulting wood pulp has been removed) is remarkably well suited for use as an absorbent for liquid air or oxygen in the manufacture of explosives or explosive cartridges.

The unleached material, which may be termed carbonized lignin residues, is generally initially obtained in a granular condition. In this form it is available in considerable quantities as a by-product of the wood pulp industry where the wood pulp is obtained by the soda or alkaline process. According to this process the wood, preferably in the form of chips, or the other ligneous material, is treated with caustic alkali, such as caustic soda, in a pressure digester at an elevated temperature. l Vhen the process is complete the removal of the wood pulp leaves a liquor which, when carbonized, preferably in the substantial exclusion of air, yields a granular carbonized mass the particles of which contain water-soluble substances, especially soda or other alkali carbonate.

The carbonized lignin residues thus obtained are now leached with hot or cold water I preferably until the residues are substantially free from water-soluble constituents, especially alkali carbonate. This action may be facilitated by acidulating the leaching water or other liquid with acid, preferably mineral acid, such as a very weak, such as a one-half per cent solution of sulphuric or hydrochloric acid. Or the treatment with acidulated water may follow the preliminary leaching step with unacidulated hot or cold water. In either case the result is to produce a substantially neutral, leached carbonized lignin residue substantially free from water-soluble substances, particularly alkali carbonalte. The effectiveness of this material for the intended purpose may in many instances be increased by heating the same, preferably to redness and preferably in substantial exclusion of air. This treatment appears to increase the capillarity or absorptive power of the residues, probably by eliminating certain volatile and gaseous substances which would have a tendency to diminish the capillarity or absorptive power of the residues.

I prefer that the material shall be used for the intended purpose in its original granular condition and preferably without crushing or grinding. However, the material may be subjected to a slight crushing action to make the particles smaller and more uniform without substantially diminishing the capillarity or absorptive power of the residues. In certain cases also the material may be ground, but in these latter cases the capillarity or absorptive power of the material seems to be considerably diminished.

The material thus obtained is now brought into contact with liquid oxygen so that it will absorb any predetermined and desired amount of this liquid substance. The liquid oxygen, due to the remarkable capillarity or absorptive power of the treated carbonized lignin residues, will be found to permeate the mass of the residues in a uniform and thoroughly satisfactory manner. The resulting explosive is characterized by its uniform quality, its stability, its high power and efiiciency as an explosive, and the similarly desirable qualities of the cartridges in which the explosive may be employed. At the same time, due to the cheap sources of the material from which the treated residues are derived, and the simplicity and economy of their manufacture, the resulting explosive is comparatively cheap, while possessin all of the desirable qualities enumerated a ove.

What I claim as my invention is:

1. The method of fabricating a liquid oxygen explosive which comprises leaching to substantial freedom from alkaline and other water-soluble substances carbonized lignin residues, and thereafter causing liquid oxygen to be absorbed by the resulting leached residues.

2. The method of fabricating a liquid oxygen explosive which comprises leaching to substantial freedom from alkaline and other water-soluble substances carbonized lignin residues, treating the leached residues with sllghtly acidulated water to render the same substantially neutral, and thereafter causng l1qu1d oxygen to be absorbed by the resultmg leached residues.

3. The method of fabricating a liquid oxygen explosive' which comprises leaching to substantial freedom from alkalineand other water-soluble substances carbonized lignin residues, treating the leached residues with slightly acidulated water to render the same substantially neutral, heating the acid-treated residues substantially to a glowing temperature to the substantial exclusion of air, and thereafter causing liquid oxygen to be absorbed by the resulting leached residues.

l. The method of fabricating a liquid oxygen explosive which comprises leaching to substantial freedom from alkaline and other water-soluble substances carbonized lignin residues, treating the leached residues with slightly acidulated water to render the same substantially neutral, heating the acid-treated residues, and thereafter causing liquid oxygen to be absorbed by the resulting leached residues.

5. Explosive material comprising leached carbonized lignin residues substantially in their original granular condition, said residues being in a substantially neutral condition, containing absorbed liquid oxygen.

6. Explosive material comprising leached carbonized lignin residues substantially uncrushed and unground so as to be in a condition of substantially maximum absorptive power, said residues being in a substantially neutral condition, containing absorbed liquid oxygen.

7. Explosive material comprising leached carbonized lignin residues substantially in their original granular condition containing absorbed liquid oxygen.

8. Explosive material comprising leached carbonized lignin residues substantially uncrushed and unground'so as to be in a condition of substantially maximum absorptive power containing absorbed liquid oxygen.

9. Explosive material comprising leached carbonized lignin residues containing ab sorbed liquid oxygen.

In testimony, whereof, I have signed my name to this specificaton this 25th day of October, 1924.

HERBERT C. BUGBIRD. 

